Chapter 12 review
Terms in this set (62)
Starts at approx. 19 days development
Neural tube at week 4 Primary vesicles
Neural tube at week 5
Primary vesicles differentiates and divides into 5 secondary brain vesicles
Each of secondary brain vesicles develops into structures of adult brain
-cerebrum or cerebral hemispheres
Space saving features that arise during brain development
The midbrain and cervical flexures move the forebrain toward the brain stem.
The cerebral hemispheres are forced to take a horseshoe-shaped course and grow posterior and laterally.
As a result they grow back over and almost completely envelop the diencephalon and midbrain.
By Week 26 the continued growth of the cerebral hemispheres causes their surfaces to crease and fold into convolutions. (which increase their surface area and allow more neurons to occupy the limited space.
Know the regions of the adult brain
Cerebral hemispheres, Diencephalon, Brain Stem (midbrain, pons, and medulla oblongata), and cerebellum.
Describe the ventricular system of the brain
Formed from the expansion of lumen of embryonic neural tube. Continuous with each other and with central canal of spinal cord.
Lateral Ventricles location
pair, located within each cerebral hemisphere.
Septum Pellucidum location
membrane that separates the anterior horns of the two lateral ventricles from each other.
Interventricular foramen location
Small channel coming from lateral ventricle. anterior to the large ass hole. In diencephalon
Third Ventricle location
channel that runs down between the lateral ventricle. Posterior to large ass hole. In diencephalon
Cerebral Aquaduct location
runs through mid brain.
Fourth Ventricle locaiton
Located in the brainstem and continous with central canal of spinal cord paired lateral apertures in walls and median aperture in roof connect to subarachnoid space. Hindbrain dorsal to pons and supieror medulla.
Be prepared to trace a drop of CSF thru the ventricular system of the brain, exiting at the 4th ventricle or entering the central canal of the spinal cord
The choroid plexus of each ventricle produces CSF.
CSF flows through the ventricles and into the subarachnoid space via the median and lateral apertures.
CSF flows through the subarachnoid space.
CSF is absorbed into the dural venous sinuses via the arachnoid villi.
Describe the CSF and function
Found in and around the brain and spinal cord, forms liquid cushion that gives buoyancy to CNS structures. function
CSF structures that produce it
Plexuses that hangs from the roof of each ventricle form CSF
CSF moves freely through the ventricles. CSF enters the subarachonoid space via the lateral and median apertures in the walls of the fourth ventricle. In the subarachnoid space CSF bathes the outer surfaces of the brain and spinal cord and then returns to the blood in the dural sinuses via the arachonoid villi.
Describe the blood-brain-barrier
Is a protective mechanism that helps maintain a stable environment for the brain.
Describe the blood-brain-barrier function
Functions hinders free exchange of substances between blood and ECF in CNS Isolates and protects CNS neurons from substances in blood. Inhibits passage of materials from the blood into brain tissues.
blood-brain-barrier structures that form it
Continuous endothelium of capillary wall (tight junctions)
Relatively thick basal lamina of capillaries
feet of astrocytes
lipid soluble molecules- fat, fatty acids, O2, CO2 alcohol, nicotine
water souluble molecules - glucose, essential aa and electrolytes
blood-brain-barrier not located
Not uniform - not present or poorly developed
hypothalamus and posterior pituitary gland
Describe the 3 meninges that surround the brain and spinal cord.
Dura mater- "tough mother" outer layer
Arachnoid mater- aka arachnoid Middle
pia mater- "gentle mother" Inner
The functions of the meninges
cover and protect CNS, protect blood vessels and enclose venous sinuses, contain CSF, and form partitions within the skull.
list the meninges and spaces in order from skull>brain or vice versa
Dura Mater- strongest meninix
Arachnoid Mater- thin elastic brain covering
Pia mater-delicate connective tissue with numerous blood vessels. cling to brain surface.
Describe the gross anatomy of the cerebrum
The telencephalon which sprouts two lateral swellings that look like mickey mouse ears become two cerebral hemispheres referred to as the cerebrum.
Gyri- Elevated ridges of tissue
Sulci- Shallow grooves
Both increase surface area of tissue
Longitudinal fissure separates the cerebral hemispheres (right down the center of brain)
Transverse cerebral fissure separates the cerebral hemispheres from the cerebellum below. (separates big brain from smaller looking brain on the bottom.)
Central Sulcus which lies in the frontal plane separates the frontal lobe from the parietal lobe.
Precentral gyrus is anteriorly of the sulcus line
Postcentral gyri in posteriorly of the sulcus line
The five lobes of each cerebral hemisphere
Frontal Lobe - where frontal is
Parietal Lobe - where parietal is
Occipital Lobe where occipital is.
Temporal Lobe where the temporal is.
Insula Lobe - is buried deep within the lateral sulcus and forms part of its floor. (side of brain).
is the largest commissures which lies superior to the lateral ventricles, deep within the longitudinal fissure.
Be able to list some general functions of the cerebral cortex
Conscious mind- Awareness, sensations, communicate, remember, understand and initiate voluntary movements
Three functional areas of the cerebral cortex
Motor- voluntary motor function
Sensory- conscious awareness of sensation
Association- to integrate diverse information for purposeful action
Describe the location and functions of motor area Primary (somatic) motor cortex
location Precentral gyrus of frontal lobe, function Conscious control of voluntary movement of skeletal muscles
Describe the location and functions of motor area Premotor cortex
location Anterior to precentral gyrus in frontal lobe. Function Controls learned motor skills of repetitous or patterned nature, Memory bank for skilled motor movements
Describe the location and functions of motor area Broca's area
present in only one hemisphere, usually left. Motor speech area- muscles of tongue, throat, lips used in speech
Generates motor program for speech
Describe the location and functions of the three sensory areas of the cortex- Primary somatosensory (somatosensory) cortex
Location Postcentral gyrus of parietal lobe. Function Receives somesthetic information from
general sensory receptors in skin
Describe the location and functions of the three sensory areas of the cortex -Primary visual (striate) cortex
Largest of all primary sensory areas. Location occipital lobe. Functions Receives visual information that originated on retina, map of visual space. Interprets visual stimuli using past visual experiences.
Describe the location and functions of the three sensory areas of the cortex- Primary auditory cortex
Location Superior margin of temporal lobe. Function Impulses from cochlear receptors related to pitch, rhythm, loudness. Permits perception of sound stimulus which we hear as speech, music, noise
Describe the location and functions of the association areas somatosensory association cortex
location posterior to the primary somatosensory cortex. Function integrate sensory inputs (temp, pressure, and so forth) relayed to it via the primary somatosensory cortex.
Describe the location and functions of the association areas Visual association area
location surrounds the primary visual cortex and covers much of the occipital lobe. Uses past visual experiences so we recognize things.
Describe the location and functions of the association areas auditory association area
location more posterior than the primary auditory cortex. Function permits perception of sounds stimulus. Sounds we hear from that past are a stored here for reference.
Each hemisphere has functions with other hemisphere
Each is specialized for certain functions
cerebral dominance left
Designates hemisphere dominant for language and analytical abilities
Aka categorical hemisphere
90% people- left
cerebral dominance right
Artistic and musical skills, appreciation
Poetic and creative side of our nature
Imagination and insight
List the three types of tracts in cerebral white matter
their function, and be able to give an example of a commisure
Commissures- commissural tracts
Commissural fibers run horizontally
Connect grey areas of 2 hemisphere so function as whole
ex. largest- corpus callosum
their function, and be able to give an example of projection tract
Fibers run vertically
Tie cortex to rest of nervous system
Ex. Corona radiata
Be able to list the 3 paired basal nuclei
Be able to list the 3 paired basal nuclei, their location in the cerebrum and their proposed functions
Caudate nucleus- -Corpus striatum
Putamen- Lentiform nucleus and Corpus striatum
Globus pallidus- Lentiform nucleus
Involved in planning and execution of movements-general pattern and rhythm
Control rhythmic, learned behaviors such as walking
Important in starting, stopping and monitoring movements
Ex. arm-swinging when walking
Be able to list the 3 paired structures that constitute the diencephalon region of the brain
Thalamus, Hypothalamus, Epithalamus
know their location relative to one another and the third ventricle
Thalamus - Protrudes into lateral ventricle, and forms the superolateral walls of the third ventricle. Makes 80% of diaceplaon
Hypothalamus - Located below thalamus, on top of brain stem. Forms inferolateral walls of third ventricle
Epithalamus- the most dorsal portion of the diencephalon. It forms the roof of the third ventricle.
Describe the functions of the thalamus
Gateway" to cerebral cortex
Relay and processing centers for sensory information traveling to cerebral cortex
Afferents from all senses and parts of body converge on thalamus and synapse with at least one of its nuclei
Sorting and editing process with sensory information
Part of limbic system
Describe the functions of the Hypothalamus
very important for homestasis
Describe the functions of the Epithalmus
1. Autonomic control center
Regulates ANS by controlling centers in brain stem and spinal cord which directly control
Heart rate and blood pressure
Respiratory rate and depth
Gi secretion and motility
2. Center for emotional response- part of limbic system
fear, pleasure, anger, aggression, biorhythms
3. Body temperature regulation
Heat-production or conservation center
4. Regulation of food intake
5. Regulation of water balance
Osmoreceptors monitor osmolarity of blood
6. Regulation of sleep-wake cycles
7. Endocrine system control
Anterior pituitary gland
Posterior pituitary gland
Supraoptic nuclei- ADH
Paraventricular nuclei- oxytocin
List the three structures that constitute the brain stem, their locations and the general functions of the brain stem
pons Primarily composed of conduction tracts
Tracts that connect cerebellum to brain stem, cerebrum and spinal cord
medulla Fibers decussate to opposite side before descend into spinal cord
List the structures located in the medulla oblongata that we discussed in class
pyramids, decussation of pyramids, and cardiovascular center.
decussation of the pyramids
Above medulla- spinal cord junction
Fibers decussate to opposite side before descend into spinal cord
cardiac centers (cardioinhibitory center and cardioacceleratory center) and vasomotor center
Dorsal inspiratory group
Ventral inspiratory group
other things medulla does
Other centers that regulate activities such as hiccuping, coughing, sneezing, sweating
Know the gross anatomy of the cerebellum
11% brain mass
Two cerebellar hemispheres connected by vermis
Functions of cerebellum
11% brain mass
Two cerebellar hemispheres connected by vermis
Symptoms of cerebellum disease
symptoms Loss of muscle tone